In today's cellular telecommunications systems, there are constant a growing desire to reduce the power consumption of the so called Radio Access Network (RAN).
A large part of the power consumption in a RAN lies in the controlling nodes of the cells in the systems, nodes which are referred to by different names in systems of different standards, but which are sometimes referred to generically as Radio base stations (RBS), or merely as radio base stations. In Wideband Code Division Multiple Access (WCDMA) systems, for example, RBSs are referred to as NodeB, and in Long Term Evolution (LTE) systems, RBSs are referred to as eNodeB.
However, regardless of the name and the system, a primary function of an RBS is that all traffic to and from users in a cell is routed via the RBS, which at least in part accounts for the large amounts of power consumed by an RBS.
In LTE and WCDMA systems, the RBS also has the function of scheduling transmissions to and from the user terminals in a cell, a function which is usually performed by a so called Media Access Control (MAC) scheduler in the RBS.
Of the components in an RBS, a major power consumer is the so called Power Amplifier, the PA. Current demands for high peak data rates, for example, at the borders of the cells require the PAs in the radio base stations to have a high output power capability. A drawback of this is that the PA in most RBSs is over dimensioned for most normal operating scenarios and also consumes more power than necessary.